The following example demonstrates that it works. You need to provide a similar copy and paste of code executed from SQL*Plus that demonstrates what happens on your system. If we can determine that when we run the same code, we get different results, then we can focus on what is different between your system and mine. It may have to do with your database characterset or client characterest.

Perhaps your index has not been synchronized since the insert of the data with the special character. You might try synchronizing and optimizing your index or rebuilding the index or dropping and recreating the index.